6-fluoro steroids



United States Patent 6-FLUORO STEROIDS Barney J. Magerlein, Kalamazoo, and George B. Spero, William P. Schneider, and John A. Hogg, Kalamazoo Township, Kalamazoo County, Mich., assignors to The Upjohn Company, Kalamazoo, Mich., a corporation of Michigan No Drawing. Application November 29, 1957 Serial No. 699,506

Claims. (Cl. 260-39745) This invention relates to 6,21-difluoro-9m-halo-21-desoxyhydrocortisone and 6,21-difiuoro-9a-halo-2l-desoxycortisone and is more particularly concerned with 6ix,9a,2l-trifiuoro-2l-desoxyhydrocortisone (6a,9u,21-t1ifluoro 115,170; dihydroxy-.4 pregnene 3,20 dione), 6oz,9a,21-trifluor o-2l-desoxycortisone (6a,9a,21-trifl uo rol7a-hydroxy-4-pregnene-3,11,20-trione), and to processes for the production thereof. 7

The compounds of this invention, 6,21-difluoro-9ahalo-2l-desoxyhydrocortisone and 6,2l-difluoro-9a-halo- ZI-desoxycortisone, possess valuable anti-rheumatoid arthritic, anti-inflammatory and glucocorticoid activities in marked degree. In addition, these compounds, are useful intermediates for the production of the l-dehydro analogues which are of particular importance because they possess marked anti-rheumatoid arthritic, anti-inflammatory and glucocorticoid activities. Thus, for example, l-dehydro-6a,9a,2Irtrifluoro-Zl-desoxyhydro-cortisone 6u,9a,2l-trifiuoro-l 1 @17 adihydroxy-1,4-pregnadiene-3,20-dione) has been found to exhibit approximately ten to fifteen timesthe anti-inflammatory activity of hydrocortisone, and in, addition has a favorable effect on body electrolyte balance. tion are useful in the treatment of inflammatory conditions of the skin, eyes and ears, of humans and of valuable domestic animals, as well as contact dermatitis and other allergic reactions. Administration of the novel steroids The compounds of this invencan be in conventional dosage forms, such as pills, tablets,

of ointments, creams,lotions and the like, with or Without coacting antibiotics, germicides or other materials forming advantageous combinations therewith.

The compounds of this invention can be prepared in accordance with the following reactions:

2,838,539 Patented June 10, 1958 CHJF EH 3 r wherein R is an organic hydrocarbon radical of one, to ten carbon atoms, inclusive, such as methyl, ethyl, phenyl, tolyl, naphthyl, or the like, methyl being preferred, and wherein X is a halogen of atomic weight between seventeen and eighty, inclusive, i. e., fluorine, chlorine or bromine.

As indicated above and described in greater detail below, the reactions embodied in the processes characterizing this invention are susceptible of variation in the specific steps leading to the final products III and V, the precise sequence selected being determined by such factors as economics and convenience.

It is an object of the present invention to provide 6,21- difluoro-9a-halo-21-desoxyhydrocortisone (III) and 6,21- difluoro-9u-halo-21-desoxycortisone (V) and more particularly to provide 6u,9a,21-trifluoro-2l-desoxyhydrocortisone and 6a,9u,21-trifiuoro-2l-desoxycortisone. A further object is to provide a process for the production of 6,21-difluoro-9a-halo-2Ldesoxyhydrocortisone and 6,2l-difluoro-9whalo-2l-desoxycortisone.

The process of the present invention comprises treating 6 fluoro-9a-ha1o-l 1 18,17 11,2l-trihydroxyl-pregnene- 3,20-dione (6-fluoro-9u-halohydrocortisone) (I) with an organic sulfonyl halide to obtain the corresponding 21- ester (II), a 2l-alkyl or aryl sulfonate of 6-fluoro-9ahalo 11,8,170:,21-trihydroxy-4-pregnene-3,ZO-dione, and thereafter treating the thus produced 2l-alkyl or aryl sulfonate with a fiuorinating agent to obtain the corresponding 6,21-difiuoro-9a-halo-1 15, l7a-dihydroxy-4-pregnene- 3,20-dione (III). If desired, the 6,21-difluoro product above can be oxidized to givethe corresponding 6,2l-difluoro 9oz halo-l7a-hydroxy-4-pregnene-3,11,20-trione (V). Alternatively, the 6-fiL1010-9ot-h8lO-11}3,17oc,21-'t1'ihydroxy-4-pregnene-3,20-dione 21-alkyl or aryl sulfonate can be reacted with an iodinating agent to produce the corresponding 21-iodo steroid, which can be fluorinated 3 to yield the 2l-fluoro steroid (HI). Similarly, when the ll-keto analogue (6-fluoro-9a-halocortisone) is utilized as the starting material in the above series of reactions, 6,21 difluoro 9a halo 17a hydroxy 4 pregnene- 3,11,20-trione (V) is produced directly without the step of oxidation of the llfi-hydroxyl.

The starting steroids for the compounds and process of the present invention are 6-fluoro-9a-halohydrocortisone and 6-fluoro-9u-ha1ocortisone and are prepared in accordance with the procedures of Preparations 1 through 25 herein. The preferred compounds containing the 17(20)- double bond have the cis configuration because they are convertible in higher yields in the oxidative hydroxylation stop than are the trans isomers, although both are operative.

In carrying out the process of this invention, 6-fluoro- 9a-halohydrocortisone is treated with an organic sulfonyl halide such as methanesulfonyl chloride, toluene-sulfonyl chloride, :toluenesulfonyl bromide, benzenesulfonyl chloride, naphthylsulfonyl chloride, or the like, the methanesulfonic acid halides, especially methariesulfonyl chloride, being preferred. .In the preferred embodiment of this invention, the starting steroid is usually reacted with the alkyl or aryl sulfonyl halide in solution in a solvent such as pyridine, benzene, toluene, or the like. Where such solvents as benzene and toluene are employed, an amount of an amine based such as pyridine at least equal to the molar amount of the sulfonyl halide should also be present to reactwith the halogen acid formed. Reaction of the alkyl or aryl sulfonyl halide is conducted preferably at temperatures between minus ten and plus sixty degrees centigrade, provided that at the lower temperatures the solvent has not solidified. Thus, for pyridine, dioxane, toluene, or the like, temperatures in the range of zero to ten degrees centigrade can be used, while for benzene only temperatures above five degrees centigrade are suitable because of therelatively high freezing point of henzene. The reaction time is usually between about four to 24 hours, after which the product, 6-fiuorO-9a-halo- 11fl,l7oc,21-trihydroxy-4-pregnene-3,20 dione 2l-alkyl or aryl sulfonate (II), is recovered in a conventional manner, such as, for-example, by evaporating the solvent until a solid residue is obtained or by diluting the reaction mixture with water and precipitating the product with dilute hydrochloric acid.

The 6-fluoro-9u-halo-l 1 8,17u,21-trihydroxy-4-pregnene- -3,20-dione 21-alkyl or aryl sulfonate can first be converted to the corresponding 21-iodo compound (IV) which is readily convertible to the 21-fluoro steroid. The 2l-iodo compound is prepared by reacting the said 21- alkyl or aryl sulfonate with an iodinating agent such as an alkali metal iodide, e. g., sodium, potassium or lithium iodide, in an oxygenated hydrocarbon solution such as an alkanone solution, e. g., acetone. A molar excess of the iodide (three to twenty moles of iodide per mole of steroid) is generally preferred for this reaction. The reaction mixture containing the 2l-alkyl or aryl sulfonate and the alkali metal iodide in solution is heated to reflux for a period of about three minutes to thirty minutes. The thus produced 6-fluoro-9a-halo-2l-iodo-l15,17cz-dihydroxy-4-pregnene-3,20-dione can then be isolated by evaporating the solvent or by drowning outwith water and filtering. For the subsequent reaction, the 21-iodo steroid can be used either in purified form as a product of recrystallization from such organic solvents as acetone, ethanol, or the like, or it can be employed directly as a crude product in the next step of the synthesis.

. The 21-iodo steroid, dissolved in a solvent such as acetonitrile, dimethylformamide or ethylene glycol, is treated with a metal fluoride such as silver fluoride, antimony fluoride, potassium fluoride, or the like, acetonitrile and silver fluoride being preferred. The metal fluoride should be added in small quantities at intervals, and the reaction mixture should be protected from light during the reaction period, which usually ranges from about 4 one-half to six hours. The reaction mixture is then concentrated and the product extracted as in previous purification steps to yield essentially pure 6,2l-difluoro-9ahalo-11,3,17ot-dihydroxy-4-pregnene-3 ,20-dione.

Alternatively, the 6 fluoro 9a halo llfl,l7ot,2l tri hydroxy-4-pregnene-3,20-dione 2l-alkyl or aryl sulfonate is reacted with a fluorinating agent such as potassium fluoride, silver fluoride or antimony fluoride in an inert solvent such as dimethyl sulfoxide, acetonitrile, dimethylformamide or ethylene glycol solution, the preferred combination being potassium fluoride in dimethylsulfoxide. The reaction is advantageously conducted under continuous heating, and it proceeds generally for a period of about six to 24 hours, fifteen to twenty hours usually being suflicient. The reaction mixture is then diluted with water and extracted withan organic solvent such as methylene chloride, chloroform, benzene, and the like, and purified in a conventional manner, as, for example, by chromatography orrecrystallization.

The foregoing reactions constituting either the principal or alternative routes can likewise be conducted on the corresponding ll-k'eto analogues.

The oxidation of 6,2l-difluoro-9a-halo-ll/3,l7m-dihydroxy-4-pregnene-3,20-dione can be carried out by a variety of methods, such as, for example, by oxidizing the said 6,2l-difiuoro steroid in acetic acid solution with chromium trioxide, using molar quantities or a slight excess, such as from ten to thirty percent excess, or by oxidizing with a haloamide or imide of an acid, such as N-bromoacetamide, N-chlorosuccinimide, or N-bromosuccinimide dissolved in pyridine, dioxane, or other suitable solvents. At the conclusion of the desired oxidation reaction, the excess oxidant is generally destroyed by addition of methyl -alcohol,.ethyl alcohol, and the like for the chromic acid oxidant or a bisulfite for N- bromoacetamide, N-bromosuccinimide and other N-halo acyl amides and imides. Therefter, the resulting 6,21- difiuoro 9a-halo-l7ot-hydroxy-4-pregnene-3,11,20-trionc is recovered by conventional means, such as by extraction with water-immiscible solvents, e. g., methylene chloride, ether, benzene, toluene or the like.

As hereinbefore indicated, the processes for the preparation of the products of the present invention are susceptible of variation. As shown in Preparations 12 through 16, 6-fluorohydrocortisone acetate is converted to 6-fluoro-9a-halohydrocortisone by introduction of the 9a-halogen into the molecule. The 6fluoro-9a-halohydrocortisone is then fluorinated at carbon atom 21 as shown in the examples. Alternatively, if desired, fluorination at carbon atom 21 can be done first and this can then be followed by halogenation at carbon atom 9. Thus, treating 6-fluorohydrocortisone with an organic sulfonyl halide is productive of the 21-su1fonate which on treatment with a fluorinating agent such as potassium fluoride or silver fluoride gives 6,21-difluoro-11,8,17a-dihydroxy- 4-pregnene-3,20-dione. The 6,2l-difluoro compound can be dehydrated with N-bromoacetamide and anhydrous sulfur dioxide in pyridine solution by permitting the reaction to continue until a negative acidified potassium iodide-starch test of the reaction-mixture is obtained. Dilution with cold water results in the precipitation of 6,21 difluoro 17a hydroxy-4,9(ll)-pregnadiene-3,20- dione, which can be purified by recrystallization from acetone. The crystalline product can then be reacted in methylene chloride-tertiary-butyl alcohol solution with perchloric acid and N-bromoacetamide or N-iodosuccinimide to producea reaction mixture from which 6,21- difluoro 9a bromo-llfi,l7e-dihydroxy-4-pregnene-3,20- dione or the corresponding 6,2l-difluoro-9a-iodo compound can be recovered by precipitation with ice water and recrystallization from acetone. The latter steroids can then be reacted in acetone solution with anhydrous potassium acetate at reflux temperatures to produce 6,21- difiuoro 9,11 oxido 17a hydroxy-4-pregnene-3,20- dione, which is recoverable from the reaction mixture by chromatography and can be further purified by recrystallization from Skellysolve B hexanes-acetone. Reaction of the said 9,11-xid0 compound in methylene chloride solution with aqueous hydrogen fluoride or liquid hydrogen fluoride in the presence of tetrahydrofuran is productive of 6,9a,2l-triiluoro-l1B,17a-dihydroxy-4-pregnene-3,20-dione. Substitution of aqueous hydrogen chloride for the hydrogen fluoride above yields 6,21- difluoro 9a. chloro-l118,17a-dihydroxy-4-pregnene-3,20- dione. If desired, either the 9a-fluoro or chloro product can be oxidized, for example, with chromic acid to give 6,911.,21 trifiuoro-17ot-hydroxy-4-pregnene-3,11,20-trione or the corresponding 9a-Chl0l0 compound.

In the foregoing processes, it should be understood that the corresponding 6,8-halo epimer can be utilized at any stage and the 6a-epimer obtained at appropriate intermediate stages by treatment of the 6,8-compound, at temperatures of zero degrees centigrade or slightly lower, in an organic solvent such as chloroform and in the presence of alcohol, withan anhydrous mineral acid, such as hydrochloric acid. Such'ternperatures should'be maintained throughout the period of addition of the acid. The reaction mixture can then be washedwith successive portions of dilute alkali and water and evaporated under reduced pressure to obtain the 6a-epimer in high yield.

The following preparations and examples are illustrative of the process and products of the present invention but are not to be construed as limiting.

PREPARATION 1 3-e2hylene ketal of methyl 3,11-dikel0-5a,6a-0xido- 1 7 (20) -[cis]-pregnen-21 -0ate To a solution of five grams of the 3-ethylene glycol ketal of methyl 3,11-diketo-4,17(20)-[cis]-pregnadien-21- oate, prepared in the manner described in U. S. Patent 2,707,184, in 100 milliliters of chloroform was added a chilled solution of 1.9 grams of perbenzoic acid dis solved in 31.5 milliliters of chloroform. The solution was maintained at about four degrees centigrade for 24 hours, and then at room temperature for 72 hours. The solution was washed with a five percent aqueous solution of sodium bicarbonate and then with water. The chloroform layer was separated, dried and the solvent distilled to give a residue of 5.3 grams'of solid. Crystal lization of this solid from methanol gave 2.24 grams of productmelting at 180 to 195 degrees centigrade, and after two crystallizations from methanol there was obtained pure 3-ethylene ketal of methyl 3,l1-dik6t05a,6a

oxide-17(20)-[cis]-pregnen-21-oate melting at 206 to 209 degrees centigrade and having an M of 37 degrees (CI-ICl and the following analysis.

Calculated for C I-1 0 C, 69.20; H, 7.75. Found: C, 69.59; H, 7.81.

PREPARATION 2 To a solution of 1.73 grams of 3-ethylene ketal of methyl 3,11-dil eto-a,6a-oxido-17(20)-[cis]-pregnen-2loate in sixteen milliliters of methylene chloride was added six milliliters of 48 percent hydrofluoric acid. The heterogeneous mixture was stirred for two hours, made slightly basic with 300 milliliters of five percent sodium bicarbonate solution, and extracted with methylene chloride. The extract was washed, dried, and evaporated to dryness to give 1.62 grams of crude solid. Purification by chromatography gave two fractions: A, 481 milligrams eluted with methylene chloride plus five percent acetone, and B, 921 milligrams eluted with methylene chloride plus ten and twenty percent acetone. Crystallization of fraction A from acetone-Skellysolve B hexanes gave 390 milligrams of methyl 3,11-diketo-5a-hydroxy-6B-fluoro- 17(20)-allopregnen-21-oate, melting point 254 to 260 de I Methyl 3 ,1 1-diketo-5a,6fl-dihydroxy-I 7 (20) -allopregnen- PREPARATION 3 Methyl 3,11-diket0-5u-hydr0xy-6l8-fluor0-17(20)411lopregnen-ZI-oate 3-ethylene ketal A mixture of 1.9 grams of methyl 3,11-diketo-5ahydroxy-6fi-fluoro-17(20)-allopregnen-21-oate, 59 milligrams of p-toluenesulfonic acid monohydrate and 31 milliliters of distilled ethylene glycol was added to 800 milliliters of benzene. The mixture was stirred and refluxed for two hours, with the condensate passing through a water trap to remove the water. After reflux the mixture was cooled, washed with water and evaporated to dryness to give a crude solid which on recrystallization from acetone-Skellysolve B hexanes gave 1.96 grams of methyl 3,11-diketo-5vt-hydroxy-6,8-fluoro-17 (20),-allopregnen-2l-oate 3-ethylene ketal, melting point 170 to 173 degrees centigrade.

Following the above procedure, substituting other dihydric alcohols for ethylene glycol, for example, 1,2- propylene glycol, 2,3-butanediol, 1,3-butanediol and 2,3- pentanediol is productive of the respective 3-alkylene ketals of methyl 3,11-diketo-5a-hydroxy-6fi-fluoro-17(20)- allopregnen-Zl-oate.

PREPARATION 4 5 (1,1 113,21-trihydroxy-6fl-fluoro-1 7 (20) -allopregnen-3-one 3-eihylene ketal To a solution of 1.96 grams of methyl 3,11diketo- 5a-hydroxy-6fi-fluoro-17 (20) -allopregnen-21-oate 3-ethylene ketal in 850 milliliters of anhydrous ether was added 3.7 grams of lithium aluminum hydride. The mixture was stirred for a period of one hour, and 200 milliliters of water was added slowly, the ether phase separating.

PREPARATION 5 The acetate was prepared by allowing 0.87 gram of 50a, 1 1 3,21-trihydroxy-6fl-fluoro-17(20) -allopregnen-3 -one 3-ethylene ketal to stand overnight in ten milliliters of acetic anhydride and ten milliliters of pyridine. The solution was then poured into ice water to give 0.92 gram of 5a,1le-dihydroxy-6fi-fluoro-2l-acetoxy 17(20) allopregnen-3-one 3-ethylene ketal, melting point to degrees centigrade, which on recrystallization from acetone-Skellysolve B hexanes gave 0.77 gram, melting point 149 to 153 degrees centigrade.

Similarly, other 2l-organic carboxylic esters of 5a,11fi, 2 l-trihydroxy-6fi-fiuoro-17(20) -allopregnen-3-one 3-ethylene ketals can be prepared wherein the 21-acyloxy group is formyloxy, propionyloxy, butyryloxy, valeryloxy, hexanoyloxy, heptanoyloxy, octanoyloxy, benzoyloxy, phenylacetoxy, or the like, by contacting 5a,11fi,21-t1iketal with the appropriate acylating agent, e. g. the.

PREPARATION 6 5oL-11]3,1 7a-trihydr0xy-6B-flu0r0-21-acetoxyall0- pregnane-3,20-dione 3-ethylene ketal To a solution of 0.77 gram of 5a,11;8-dihydroxy-613- fluoro-21-acetoxy-l7(20)-allopregnen-3 one 3 ethylene ketal in 35 milliliters of tertiary butyl alcohol was added one milliliter of pyridine, 1.9 milliliters of N-methylmorpholine oxide peroxide solution, and 13.1 milligrams of osmium tetroxide (9.1 milliliters of tertiary butyl alcohol solution containing 1.44 milligrams of osmium tetroxide per milliliter). The solution was stirred for a period of 2.5 hours and fifteen milliliters of five percent sodium hydroxsulfite was added. Stirring was continued for an additional ten minutes, at which time 0.7 gram of finely ground synthetic magnesium silicate was mixed into the solution for a period of twenty minutes and then removed by filtration. The filtrate was evaporated to dryness-under reduced pressure at a temperature of less than fifty degrees centigrade. The residue was dissolved in methylene chloride, washed with water, dried and evaporated to dryness. This residue was crystallized from acetone-Skellysolve B hexanes to give 0.47 gram of 5a,11B,17a-trihydroxy-6/3-fluoro-21 acetoxyallopregnane- 3,20-dione 3-ethylene ketal, melting point 220 to 228 degrees Centigrade.

PREPARATION 7 5 04,1 1,8,1 7 a-trihydroxy-d B-fluoro-Z 1 -acetxyall0- pregnane-3,20-dione A solution of 0.47 gram of a,11'5,17a-trihydroxy-6pfiuoro-21-acetoxyallopregnane-3,20-dione 3-ethylene ketal in 35 milliliters of acetone and four milliliters of l N sulfuric acid solution was gently boiled on a steam bath for ten minutes, cooled and neutralized with dilute sodium bicarbonate solution. Addition of water followed by cooling gave 0.33 gram of 50L,l1,3,17oc-il'lhYdI0XY-6fifiuoro-Zl-acetoxyallopregnane-3,ZO-dione, melting point 230 to 240 degrees centigrade.

PREPARATION 8 A solution of 100 milligrams of 5a,llfi,l7a-trihydroxy- 6B-fiuoro-2l-acetoxyallopregnane-3,20-dione in 4.9 milliliters of acetic acid and 0.1 milliliter of water was refluxed for a period of one hour, cooled, diluted with fifty milliliters of water and evaporated to dryness under reduced pressure. The residue was chromatographed over synthetic magnesium silicate to give one fraction (77 milligrams) eluted with methylene chloride plus ten percent acetone. Crystallization from acetone-Skellysolve B hexanes gave 38 milligrams of 6,8fluorollfi,17adihydroxy-21-acetoxy-4-pregnene 3,20 dione (6B fluorohydrocortisone acetate), melting point 210 to 218 degrees centigrade. Infrared data and ultraviolet data were in agreement with the structure.

PREPARATION 9 6 a-fiuoro-I 1 l3,17a-dihydr0xy-21 -acetoxy-4-pregnene-3 ,20- d ione (6 a-fluorohyd rocortisonc acet te) washed with diluted aqueous sodium bicarbonate solution, dried over anhydrous sodium sulfate, and evaporated to dryness under reduced pressure at sixty degrees centigrade. Crystallization of the residue from acetone-Skellysolve B hexanes gave 42 milligrams of the isomerized product, c fiuoro 1lfi,17a dihydroxy-2l-acetoxy-4-pregnene- 3,20-dione, which melted at 203 to 210 degrees centigrade.

PREPARATION 1O 6a-flu0r0-11,8,17a,21-trihydroxy-4-pregnerte-3,20-dione (6 a-fluorohydrocortisone) A solution of 1.1 grams of 6ot-fluoro-1lB,l7a-dihydroxy-Zl-acetoxy-4-pregnene-3,20-dione, one gram of potassium bicarbonate, 100 milliliters of methanol and fifteen milliliters of water were mixed together and purged with nitrogen to remove dissolved oxygen while stirring at 25 degrees centigrade for four hours. The solution was then neutralized by addition of acetic acid and distilled under vacuum to remove the methanol. The residue was extracted with 100 milliliters of methylene dichloride, and the extract was dried over sodium sulfate and passed through a column containing eighty grams of synthetic magnesium silicate. The fraction eluted with Skellysolve B hexanes plus twenty and thirty percent acetone weighed 770 milligrams, representing a yield of 77.5. percent. Recrystallization of a portion of this crude product from ethyl acetate-Skellysolve B hexanes gave crystals melting at 192 to 195 degrees centigrade.

PREPARATION l l 6 ,S-fluoro-I 711,21-dihydr0xy-4-pregnene-3,11 ,ZO-trione (6 B-fluoracortisone To a solution of 0.5 gram of 6fi-fluoro-11B,l7u,21-trihydroXy-4-pregnene-3,20-dione and one milliliter of pyridine in 35 milliliters of tertiary butyl alcohol was added 250 milligrams of N-bromoacetamide. After maintaining at room temperature for sixteen hours, the reaction mixture was diluted with 25 milliliters of water containing 250 milligrams of sodium sulfite and concentrated to about twenty milliliters at which point precipitation took place. The thus obtained precipitate was collected on a filter and recrystallized three times from ethyl acetate and Skellysolve B hexanes to give 6fl-fluoro-l7a,2l-dihydroxy- 4-pregnene-3,1 1,20-trione.

Substitution of the corresponding 6a-epimer for the starting material above is productive of 6oz-fl110rO-17a,2l dihydroxy-4-pregnene-3,11,20-trione. Alternatively, the 6a-epin1er can be obtained from the corresponding product by the procedure of Preparation 9.

PREPARATION l2 To a solution of one gram of 6a-fiuorohydrocortisone acetate in ten milliliters of pyridine was added 0.4 gram of N-bromoa'cetamide. The mixture was allowed to stand under nitrogen for twenty minutes, at which time it was cooled to five degrees centigrade. While stirring, sulfur dioxide was passed over the surface until the solution gave no color change with acidified starch-iodide paper. The temperature of the reaction mixture was not allowed to go above twenty degrees centigrade during the sulfur dioxide addition. The mixture was then allowed to stand for five minutes and was poured into milliliters of ice-water, resulting in precipitation of 915 milligrams of crude solid, melting point to 202 degrees centigrade. Crystallization from acetone gave 511 milligrams of 6afluoro-l7a-hydroxy 21 acetoxy 4,9(11). pregnadiene- 3,20-dione, melting point 214 to 218 degrees Centigrade. The analytical sample melted at 220 to 222 degrees centigrade. Analysis gave [0:1 plus 73 degrees (acetone) and the following:

Analysis-Calculated for C I-1 0 1: C, 68.30; H, 7.23; F, 4.70. Found: C, 68.77; H, 7.57; F, 4.77.

9 PREPARATION 13 6a fluoro 9a homo-115,17a-dihydrxy-21-acetoxy -4- pregnene 3,20 dz'one (6a-flu01'0-9u-bromahydrocortisane acetate) in an ice bath, thirty milliliters of water was added with stirring. On filtering the crystalline product, followed by Washing with water and drying, a yield of 480 milligrams of essentially pure 6a-fiuoro 9.0: bromo-11p,17a-dihydroxy-21-acetoxy-4-pregnene 3,20 dione, melting point 163 to 166 degrees centigrade (with decomposition) was obtained. The product was used in the succeeding example without further purification.

Substitution of N-iodosuccinimide for the N-bromoacetamide in the foregoing reaction is productive of the corresponding 9ot-iodo product, 6u-fluoro-9a-iodo-115,1711- dihydroxy-Z1-acetoxy-4-pregnene-3,20-dione.

PREPARATlON .14

6a fluoro 95,1113 oxide 17a hydroxy 21 -acet0xy- 4-pregnene-3,20-di0ne A mixture of 2.816 grams of 6a-fluoro-9a-bromo- 11,8,170: dihydroxy 21 .acetoxy 4 pregnene 3,20- dione (6a-fiuoro-9a-bromohydrocortisone acetate) 2.816 grams of potassium acetate, and ninety milliliters of acetone was stirred and heated at reflux temperature for eighteen hours. The reaction mixture was then concentrated to about one-half the original volume and cooled in an ice bath. Addition ,of 250 milliliters of water gave 2264 grams of 6oc-flu0rO-9BJLB-QXidO-17pt-hYdTOXy-21- acetoxy-4-pregnene-3,20-dione, melting point 195 to 200 degrees centigrade (with decomposition); The analytical sample, recrystallized from acetone, melted at 197 to 200 degrees centigrade. degrees (acetone) and the following:

Analysis.Calculated .for C- gH O F: C, 65.70; H, 6.95; F, 4.52. Found: C, 65.76; H, 7.03; F, 4.24.

PREPARATION 15 601,90: difluoro 11 8,1711 dihydroxy 21 acetoxy 4- pregnene-3,20-dione (6 1,9a-difluorohydrocortisone ace rate) To 3.41 grams of liquid hydrogen fluoride cooled'in a Dry ice bath, was added, portion-wise, a slurry of 1.875

grams of 60c-fll1010-9/3,1 1/3-oxido 17u-hydroxy-2'1-acetoxy- 4-pregnene-3,20-dione in 5.97. grams of tetrahydrofuran (distilled over NaOH) and twenty milliliters of methylene chloride which had similarly been cooled in a Dry Ice bath. The steroid dissolved completely. After standing at zero to five degrees centigrade for seventeen hours, the reaction mixture was poured slowly into a stirred mixture of 300rnilliliters of ice-water, fifty milliliters of methylene chloride, and twenty grams .of sodium bicarbonate. The mixture was stirred for a few minutes, the methylene chloride layer was separated and the water phase extracted with two fifty-milliliter portions of fresh methylene chloride. The combined'methylene'chloride solutions were washed with water and dried, Attempts to crystallize the product by addition of Skellysolve B hexanes gave only oil. The oil was again dissolved by addition of methylene chloride and chromatographed over synthetic magnesium silicate. One long fraction of 1.496

Analysis gave [111 plus 28 '10 grams down from the column, which according tothe papergram consisted of four materials in the ratio of 5:25 :65 :5. This fractiongave crystalline fractions of material upon cooling.

All of the crystallization fractions were combined and the whole column fraction was acetylated overnight with ten milliliters of acetic anhydride in ten milliliters of pyridine. The acetylation mixture was poured into icewater and extracted with methylene chloride. The extract was washed with dilute acid, dilute base, water, dried and put over a synthetic magnesium silicate column. A papergram of this crude material showed two spots in the ratio of 20:80. The fraction weighing 1.075 gram, eluted from the column with fifteen and twenty percent acetone in Skellysolve B hexanes was recrystallized several times from ethyl acetate and gave 180 milligrams of constant melting product 6a,9a-difiuoro- 115,170: dihydroxy 21 .acetoxy 4 pregnene 3,20- dione, melting point 220 to 225 degrees centigrade. Analysis gave [u] plus 115 degrees (acetone) and the following:

Analysis.Calculated for C H O F C, 62.71; H,

Found: C, 62.85; H, 7.22; F, 8.67.

Substitution of aqueous hydrogen chloride for the hydrogen fluoride above is productive of the corresponding 9a-chloro product, 6oc-fi1l01O-9zx-Chl0l'O-l l,8,17u-dihydroxy-Z l-ac etoxy-4-pregnene-3 ,20-dione.

PREPARATION 16 611,90: difluoro 1 16,] 704,21 zrihydroxy 4 pregnene- 3,20-dione (6a,Qa-difluorohydracortisone) Nitrogen was bubbled through a solution of 0.33 gram of 6oz,9a difinoro- 115,170 dihydroxy 21 acetoxy- 4-pregnene-3,20-dione (611,9a-difiuorohydrocortisone acetate) in 33 milliliters of methanol for fifteen minutes. To this was added a solution of 0.33 gram ofpotassium bicarbonate in four milliliters of water likewise treated with nitrogen. After stirring under nitrogen for five hours, the base was neutralized by the addition of 2.5 milliliters of five percent hydrochloric acid. The mixture was then concentrated under reduced pressure at fifty degrees .centigrade to about five milliliters. The residue was taken up in ethyl acetate, washed, dried and evaporated to dryness. Crystallization from acetone-Skellysolve B hexanes yielded 0.27 gram of 6a,9u-difluorollpt,17a,2l trihydroxy 4 pregnene 3,20 dione (6a,9a-difluorohydrocortisone), melting point 210 to 218 degrees Centigrade. The analytical sample melted at 214 to 217 degrees centigrade. Analysis gave [all plus 115 degrees (acetone) and the following:

Analysis-Calculated for C H O F C, 63.30; H, 7.08; ,F, 9.54. Found: C, 63.60; H, 7.39; F, 8.4-8.

PREPARATION 17 6a fluoro 9a chloro 11 3,17a,21 trihydroxy 4- pregnene 3,20 dione (6a fluoro 9a chlorohydroeortisone) Following the procedure of Preparation 16, substitution of 6u-fiuoro-9ct-chlorohydrocortisone acetate from Preparation 15 for 6u,9a-difluorohydrocortisone acetate, is productive of 6a-fiuoro-9a-chlorohydrocortisone.

PREPARATION 18 pregnene 3,20 dione (6oz. fluoro c bromohydrocortisone) 1*! acid conditions, such as, for example, methanolic hydrochloric acid.

PREPARATION 19 A solution was prepared containing 0.5 gram of 6a,9adifiuoro ll;3,l7a dihydroxy 21 acetoxy 4 pregnene-3,20-dione (6a,9a-difluorohydrocortisone acetate) 0.15 gram of chromium trioxide, ten milliliters of glacial acetic acid and one-half milliliter of water. This mixture was stirred and maintained at room temperature for eight hours. Thereafter, the excess oxidant was destroyed by addition of methanol and the mixture was poured into fifty milliliters of ice water. The resulting precipitate was collected on a filter and recrystallized three times from ethyl acetate-Skellysolve B hexanes to give 6a,9czdifluoro 17cc hydroxy 21 acetoxy 4 pregnene 3, -1 1,20-t1i0ne.

PREPARATION 20 6a fluoro 9a chloro 17a hydroxy 21 acet'oxy 4- pregnene 3,11,20 trione (6a fluoro 9oz clorocortisone acetate) Following the procedure of Preparation 19, oxidation of Got-fluoro-9ot-chlorohydrocortisone acetate of Preparation 15 is productive of 6ix-fiuoro-9u-chlorocortisone acetate.

PREPARATION 21 6o: fluoro 90c brm0 17a hydroxy 21 acetoxy- 4 pregnene 3,11,20 trione (6a. fluo ro 9a bromocortisone acetate) Following the procedure of Preparation 19, oxidation of 6oz-fluoro-9u-bromohydrocortisone acetate of Preparation 13 is productive of 6a-fluoro-9a-bromocortisone acetate.

PREPARATION 22 Following the procedure of Preparation 16 but substituting 60:,90t-dlfl110l0C0I'l2iS01'18 acetate as the starting material therein is productive of 6u,9ot-difiuorocortisone.

PREPARATION 23 Following the procedure of Preparation 16 but substituting 6oc-fiUOl'O-90t-Chl0IOCOItiSOI16 acetate of Preparation 20 as the starting material therein is productive of 6a-fiuoro9a-chlorocortiscne.

PREPARATION 24 Following the procedure of Preparation 16 but substituting Got-fillOIO-9a-bI'OmOCOI'tlSOI1e acetate of Preparation 21 as the starting material therein is productive of 6a-fiuoro-9rx-bromocortisone.

PREPARATION 25 6B-epimers Substituting 6,3-fiuorohydrocortisone for starting material in Preparation 12 and retaining the 6,3 configuration in subsequent steps by careful maintenance of near neutral reaction condition, 6fi-epimers, such as 65,9u-difi11orohydrocortisone, 6B-fiuoro-9u-chl0rohydrocortisone, 6,8- fluoro 9a bromohydrocortisone, 6 8,911 difluorocortisone, 65-fluoro-9a-chlorocortisone and 6a-fll101'0-9abromocortisone, are produced. The thus obtained 6t3- epimers yield the 6tZ-6pll'l16I'S by treatment with acid or base in an organic solvent.

EXAMPLE 1 To a solution of 0.5 gram of 6u,9a-difluoro-ll[i,l7a, 21 trihydroxy-4-pregnene-3,2O-dione in six milliliters of pyridine previously cooled to zero to five degrees centigrade was added 0.55 milliliter of methanesulfonyl chloride. The reaction mixture was stirred at six degrees centigrade for sixteen hours, and was then diluted with two milliliters of water and poured into milliliters of cold five percent hydrochloric acid to precipitate the solid mesylate 6u,9adifluoro-l1p1,17a,2l-trihydroxy-4- pregnene-3,20-dione 21-methanesulfonate. The product, after filtration, weighed 0.62 gram and was used without further purification.

EXAMPLE 2 6a,9a,21 trifluoro 115,170: dihydroxy 4 pregnene- 3,20 dione (6a,9oz,21 trifluoro 21 desoxyhydrocortisone) To a solution of 0.57 gram of 6a,9adifiuoro-2l-iodo- 11,8,17a-dihydroxy-4-pregnene3,ZO-dione in 55 milliliters of acetonitrile at fifty to sixty degrees centigrade in the dark, was added 0.4 milliliter of fifty percent aqueous solution of silver fluoride. Addition was done in three equal portions at one-half hour intervals. After maintaining at this temperature for a total of one and onehalf hours, the temperature was lowered to forty to fifty degrees centigrade for an additional two and one-half hours. The solvent was then removed under reduced pressure at fifty degrees centigrade and the black residue was digested with three fifty-milliliter portions of acetone. The product, contained, in the acetone solution, was purified by chromatography over a column of synthetic magnesium silicate and crystallization from acetone-Skellysolve B hexanes to give 6oz,9a,21-tt'iflI1OI'O-11fi,-17oz-dihY- droxy-4-pregnene-3,20-dione having a melting point of 210 to 235 degrees centigrade.

EXAMPLE 4 6oz,9u,21 trifluoro 11fi,17oc dihydroxy 4 pregnene- 3,20 dione (6u,9ot,21 trifluoro 21 desoxyhydrocortisone) A mixture of 200 milligrams of 6:2,9zz-difll10I'O-llfl, 174:,2l-trihydroxy-4-pregnene-3,2O-dione 21-methane sulfonate and 100 milligrams of potassium fluoride in two milliliters of dimethylsulfoxide was heated on a steam bath for seventeen hours. The reaction mixture was diluted with fifty milliliters of methylene chloride and washed three times with ten milliliters of water. After drying over sodium sulfate, the methylene chloride solution was passed over a column of ten grams of synthetic magnesium silicate. Elution with Skellysolve B hexanes plus acetone yielded 6a,21-difluoro-11/3,17a-dihydroxy-4- EXAMPLE 6 60,21 difluoro 9a bromo 115,171; dihydroxy 4- pregnene 3,20 dione (611,21 difluoro 9oz bromo- 21 desoxyhya'rocortisone) Following the procedures of Examples 1 through 4 but substituting 6a-fluoro-9u-bromohydrocortisone of Preparation 18 as starting material is productive of 6a,2ldifluoro-9a-bromo-2l-desoxyhydrocortisone.

EXAMPLE 7 6 a,9ot,21 trifluoro 17a hydroxy 4 pregnene 3,11,20- trione (6a,9u,21 trifluoro 21 desoxycortisone) A solution was prepared containing 0.5 gram of 60:,9a, 21 triflu-oro 115,17a dihydroXy 4 pregnene 3,20- dione, 0.15 gram of chromium trioxide, ten milliliters of glacial acetic acid and one-half milliliter of water. This mixture was stirred and maintained 'at room temperature for eight hours. Thereafter, the excess oxidant was destroyed by addition of methanol and the mixture was poured into fifty milliliters of ice water. The resulting precipitate was collected on a filter and recrystallized from ethyl acetate to give 6u,2l-difiuoro-17ct-hydroXy-4- pregnene-3,1 1,20-trione.

EXAMPLE 8 6ot,90t,21 trifluoro 17a hydroxy 4 pregnene 3,11, 20 trione (604,904,21 lrifluoro 21 desoxycortisone) In the same manner shown in Examples 1 and 4, treat. ing 6a,9a-difluoro-17a,21-dihydroxy-4-pregnene-3,l 1,20- trione with methanesulfonyl chloride in pyridine solution yields 6u,9u-difluoro-17u,21-dihydroXy-4-pregnene-3, 1 1- 20-trione ZI-methanesulfonate. Heating the said 21- methanesulfonate with potassium fluoride in dimethylsulfoxide produces 6a,9a,21-t1'lflll0r0-17oz-hYdIOXY-4- pregnene-3 ,11,20-trione.

EXAMPLE 9 611,21 difluoro 9a chloro 17a hydroxy 4 pregnene 3,11,20 trione (6:121 difluoro 9a chloro- 21 desoxycortisone) Following the procedure of Example 7, oxidation of 6a,2l-difiuoro-9a-chloro-2l-desoxyhydrocortisone of Example is productive of 6a,2l-difluoro-9u-chloro-2ldesoxycortisone.

Alternatively, 6a,21-dlfill0I0-9a-Chl0rO-2l-dCSOXYCOI'tisone is prepared by following the procedures of Examples 1 through 4 and substituting 60t-flllOI'O- (X-ChIOI'OCOItlS'OIIe of Prepartion 23 as starting material therein.

EXAMPLE 60;,21 difluoro 9a bromo 17oz hydroxy 4 pregnene 3,11,20 trione (60:,21 difluoro 9oz bromo- 21 desoxycortisone.)

Following the procedure of Example 7, oxidation of 6m,2l-difiuoro-9a-bromo-2bdesoxyhydrocortisone of Example 6 is productive of 60,2l-difluoro-9a-bromo-2ldesoxycortisone.

Alternatively, 6a,21-difluoro-9u-bromo-2l-desoxycortisone is prepared by following the procedures of Examples 1 through 4 and substituting 60t-fl110l'O-906-b1'OIHOCOI'ilS0116 of Preparation 24 as starting material therein.

M 14 EXAM PLE 11 6fl-epimers Substituting 6,8,9br-difluorohydrocortisone for the starting material in Example'l andretaining the 6;? configuration in subsequent stepsby careful maintenance of near neutral reac'tion conditions, GB-epimers, such as 6fi,9a,21- trifluoro 11 8,1700 dihydroxy 4 pregnene 3,20- atone, 6p; 21 difluoro 9a chloro llfi,l7rx dihydfdxy 4 pregnene 3,20 dione, 63,21 difluoro 9abromo 11,8,17a dihydroxy 4 pregnene 3,20 dione, 65,911,21 trifiuoro 17a hydroxy 4' pregnene 3,11,20 trione, 6,8,21 difluoro 9a chloro 17a hydroxy 4 pregnene 3,11,20 trione, 613,21 difluoro- 9u bromo 17cc hydroxy 4 pregnene 3,11,20- trione, are produced which can be isolated from the reaction mixture. The thus obtained 6/3-epimers yield the Ga-epimers by treatment with acid or base in an organic solvent.

EXAMPLE 12 1 -dehydro-6a,9a,21-trifluor0-21 -des0xyhydrocortis0ne Three l00-milliliter portions of a medium, in 250-milliliter Erlenmeyer flasks, containing one percent glucose, two percent corn steep liquor (sixty percent solids) and tap water, were adjusted toa pH of 4.9. This medium was sterilized for 45 minutes at fifteen pounds per square inch pressure and inoculated with a one to two day growth of Sepfomyxa afiinis A. T. C. C. 6737. The Erlenmeyer flask was shaken at room temperature (about 26 to 28 degrees centigrade) for a period of three days. At the end of this period 300-milliliter volume was used as an inoculum for five liters of the same glucose-corn steep liquor medium which in addition contained five milliliters of an antifoam compound (a mixture of lard oil and octadecanol). The fermenter was placed into the water-bath, adjusted to 23 degrees Centigrade and the contents stirred 300 R. P. M.) and aerated (0.3 liter air to five liters of beer). After twenty hours of incubation, when a good growth had been developed, one gram of 6a,9oc,21 trifiuoro 21 desoxyhydrocortisone plus one-half gram of 3-ketobisnor-4-cholen-22-al, dissolved in sixteen milliliters of dimethylforrnamide was added and the incubation carried out at the same temperature (28 degrees centigradc) and aeration for a period of 72 hours (final pH 8.3). The mycelium was filtered off and extracted with three ZOO-milliliter. portions of acetone. The beer was extracted with three one-liter portions of methylene chloride and thereupon the extracts of the beer and acetone were combined, dried over anhydrous sodium sulfate and evaporated. The resulting residue was purified by chromatography over a Florisil anhydrous magnesium silicate column and crystallization from acetone Skellysolve B hexanes to give l-dehydro-6a,9u,2l-trifluore-21-desoxyhydrocortisone of melting point 267 to 272 degrees centigrade (with decomposition).

Following the procedure above but substituting 611,911, Zl-trifluoro-Zl-desoxycortisone acetate as starting material therein is productive of 1-dehydro-6a,9u,21-trifiuoro-21desoxycortisone.

It is to be understood that the invention is not to be limited to the exact details of operation or exact compounds shown and described, as obvious modifications and equivalents will be apparent to one skilled in the art. The invention is therefore to be limited only by the scope of the appended claims.

We claim:

1. A compound selected from the group consisting of 6,21 difluoro 9oz halo- 21 desoxyhydrocortisone and 6,21 difluoro 9a halo 21 desoxycortisone, wherein the Qua-halogen is of atomic weight between seventeen and eighty, inclusive. I

2. A compound selected from the group consisting of 60:,21 difluoro 9a halo 21 desoxyhydrocortisone and 60:,21 difluoro 9oz halo 21 desoxycortisone,

15 wherein the 9u-halogen is of atomic weight between seventeen and eighty, inclusive.

3. 60,21 difluoro 9a halo 21 desoxyhydrocortisone, wherein the 9a-halogen is of atomic weight between seventeen and eighty, inclusive.

4. 6oz,9a,2l-trifluoro-Zl-desoxyhydrocortisone.

5. 60,2l-difluoro-9a-chloro-2l-desoxyhydrocortisone.

6. 6oz,21-difluoro-9a-bromo-2l-desoxyhydrocortisone.

7. 6a,21 difiuoro 9a halo 21 desoxycortisone, wherein the 9u-halogen is of atomic weight between seventeen and eighty, inclusive.

16 9. 6u,21-difluoro-9a-chloro-2l-desoxycortisone. 10. 60,21-difluoro-9u-bromo-2l-desoxycortisone.

References Cited in the file of this patent UNITED STATES PATENTS Herr Nov. 19, 1957 Nussbaum Nov. 26, 1957 Tannhauser et 21.: J. A. C. S. 78, 2658-9 (1956). Herz et al.: J. A. C. S. 78, 4812 (1956). 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 6,21 - DIFLUORO - 9A - HALO- 21 - DESOXYHYDROCORTISONE AND 6,21 - DIFLUORO - 9A - HALO - 21 - DESOXYCORTISONE, WHEREIN THE 9A-HALOGEN IS OF ATOMIC WEIGHT BETWEEN SEVENTEEN AND EIGHTY, INCLUSIVE. 